Built as a heavy freight locomotive, and powered by a 645E3 V-20 turbo-charged diesel engine. It was the first V20 engine ever made, overcoming two design challenges: making a very long crankshaft tough enough to take the torque it would endure when in service; and the firing order for 20 cylinders. The engine is 65'8" long, and weighs approximately 391,000 pounds.